Illuminated sign



July 13 1926.

A. B. RAMSDELL ILLUMINATED S IGN Filed Oct. 18, 1922 Patented July 13,1926.

UNrrED STATES PA'riszN'rh oFFlcE.

LB'LHUB B. BAMSDELL, 0l' CICAGO, ILLINOIS; ADA. VIOLA RAMSDELL EXECUTRIXOl' SAID ABTHUBVB. RAISDELL, DECEASED.

ILLUMINATED SIGN.

Application led October 18, 1928. Serial No. 585,943.

on the face thereof, even where no legiblel character appears on theface of the sign. These rays will enter the sign through the face and bereflected by any interior reflecting surface so that`the sign will belegible, although not illuminated from within by the means provided forsuch a pur- .ose.

P Such legible Showing of the sign as the result of primary exteriorillumination I refer to as a phantom.

In brief, my invention comprises a closed compartment with a suitablylocated and focused source of illuminationY on the interior thereof andwith the side to be illuminated formed of an opaque backgroundsurrounding a translucent or transparent character, which translucent ortransparent character is so constituted that suflicient light toilluminate the same cannot pass therethrough from the exterior and bereflected back from the interior.

Preferably also this illuminated face of the compartment comprises asand-blasted, etched or similarv surface, preferably on the exteriorthereof.

The many other objects and advantages of the present invention will bebetter understood by reference to the following speciication whenconsidered in connection with the accompanying drawing illustratingselected embodiments thereof, in which Fig. 1 is a perspective view ofthe sign or signal comp ete.

Fi 2 is a vertical section of the line 2 2 of Fig. 1.

Fig. 3 is a fragmentary top view.

display an emblem, letter,

Fig. 4 is an enlarged transverse sectional view of a portion of thefront plate or panel of the sign or signal.

Fig. 5 is a rear elevation of the front panel, and

Fig. 6 is a fragmentary side elevation of the sign or signal providedwith a visor.

Referring tov the drawings, the signal is shown as provided with a boxor casing 10 which in the present embodiment is divided intocompartments by a series of parallel `partitions 11 extending from frontto rear thereof. The front face of each compartment is closed by a frontplate or panel 12 forming a portion of the sign. These panels 12 aremounted in suitable frames 13 on the casing 10 and are insertabletherein at the top thereof. One letter is formed on each of the panels.A lamp 14 is pro- `vided in each compartment and a reflector 15 ispreferably mounted in rear of the lamp and focused on the character atthe front of the compartment.

The panel 12 is preferably made of heavy glass such as pressed orplate-glass having a raised letter 16 cast upon the inner face thereofwith the rear face 17 of this letter preferably provided with aprismatic surface. The entire front face 18 of the panel -12 is ground,sand-blasted or otherwise treated so that the letter thereon isabsolutely invisible except when the lamp behind the same is burning.The portion of the back-face or background 19 of the panel not includedin the letter is rendered impervious to light by the use of black paintor any other suitable means. When the sign is intended to indicatedanger, it is customary to use a panel of ruby glass.

It is believed that this raised letter by offering a sufficient depth ofglass operates materially in obstructing and diiusing the entry ofexterior light and the free return passage of such exterior light whenreflected back by the reflector. Also by providing a `raised letter, theopaque background is more readily applied when 'for example the surfaceof the glass surrounding the raised letter is enameled or otherwiserendered opaque. p Q

The sign or signal may be either automatically or manually controlled.In the case of a warning signal at a railway crossing, an approachingtrain will automatically cause current to e supplied to the lamps withinthe compartments and the signal will be illuminated and will continue toshow4 until the crossing is again safe for highway traiic. This signalmay be used to replace the familiar warning bell or may be used inrconjunction therewith.

The inding, sand-blasting or like treatment orthe entire front face ofthe panel and particularly that portion directly in front of the letterforms a screen which con` ceals the letter and prevents the assagethrough the panel of sufficient light rom an 'external source to producephantom signals due to the reflection of such light from within. Theraised letter on the rear face of the panel facilitates the applicationof the paint forming the opaque background, obstructs and diffuses anylight entering from without and materially strengthens the illuminationof the sign. The prismatic rear lface of the letters brightens theletters when viewed from the front and the illumination of the sign isfrom within and also co-operates with the ground face of the panel toprevent phantom signals.

While it is advantageous to use a divided casing with a separate lampand reflector in each compartment thereof, my improved panel or frontplate construction is also applicable to any type of illuminated signand particularly to traiiic signals or indicators for automobiles. Morethan one character may obviously be placed upon a panel.

For best results, however, the raised letter should afford suchobstruction to the passage of light from the exterior that each letterwill require a separately focused light in a compartment excludin allother interior light, to properly illuminate it. This arrangement solocates the reflector that it will not reflect external light in suchmanner as to provide a phantom.

While I have shown and described a prismatic back, the claimscontemplate any corrugation or other treatment or formation of the backwhereby a similar light effect is attained.

Frosting may be considered generic for any suitable treatment of frontsurface to render it relatively non-transparent while remainingtranslucent. In the resent application the term colored is intended toindicate a color other than white.

With reference to the foregoing specification and the following claimswhich are not to be limited to the specific structure shown exce t wheresuch limitation is necessitated by t e prior art, it is to be noted:

Lussac-is For convenience the term translucent has been used in itssecondary meaning as applying to a substance having the quality o passinlight which substance may or may not e4 transparent, except where theterm is used with an indicated more limited meaning or such more limitedmeaning is necessitated by the prior art. v

While I have found the simplest and most convenient way of treating theexteriorx face of the sign is to sand-blast that face, it will beunderstood that the purpose of suoli treatment is supposed to provide asurface which will not to any considerable degree reflect a lightdirected thereon as such reection tends to confuse the clarity of thedanger signal, and also to provide for a diffusion of light entering thesignal chamber from the exterior, while not affording an objectionablebarrier for the assage of the concentrated and focused ight from theinterior.

For the second purpose above specified, it is immaterial whether thesand-blasted surface is on the exterior or is interposed at anyeffective point between the exterior and the interior of the sign.

Also so far as the broad idea of the invention is concerned, it isimmaterial whether the sand-blasted or similar surface is integral withthe translucent or transparent letters or characters of the sign, or ison a separate element. I note also that while in its broader aspects Icontemplate the use of any suitable reiector, I have obtained the bestresults by means of a so-called X-ray reflector now on the market.

While I have shown and described the back of the letter or character asformed with prismatic surfaces, and in practice have found suchstructure most ei'ective for the purposes intended, the term prismaticmay be considered as suiciently generic for the purposes of thisapplication to indicate any formation of the rear surface of thecharacters or letters which will effectively interrupt and diffuse lightrays entering from the exterior while either affording no materialobstruction to light rays reflected from the source of illumination inthe interior, or serving to increase the effective 'illumination fromtheinterior.

While I have attained the results described by means of a devicecomprising raised letters formed integral with a relatively thin frontsheet or pane of glass, it is obvious that to some extent at least thesaine results and advantages will be attained by making the entire sheetof glass of such thickness that the light rays have to traverse the samedepth of glass as when such raised lettersare used. Y

It' is believed that if desired the effect of diffusion of enteringlight without mate- 'rially interfering with intentional illuminallt)tion may be substantially assisted by the character of the glass ofwhich the legible characters are made, such as Alba glass now incommercial use.

l am aware that the sign construction herein vshown and described iscapable of material modification Without departing from the spirit of myinvention, and I reserve the rlght to make such a's fairly falls withinthe scope ot' the following claims.

1 claim 1. In a sign, a panel of transparent material having a raisedcharacter on the back thereof and integra] therewith, and au opaquebackground having an opening therein through which said characterprojects, the front face of said panel being frosted opposite saidcharacter.

2. In a sign, a panel of transparent material having a raised characterformed on the back thereof With the rear face of said characterprismatic, and a layer of opaque material on said back except in theportions occupied by said character, the front facel of said plate beingfrosted.

3. An illuminated sign comprising a casing divided by partitions into aplurality of separate compartments open at the front, a lamp in eachcompartment, and a closure for each of said compartments including aplate of translucent material having a raised character on the backthereof and integral therewith, and a layer of opaque material on saidback except in the portion occupied by said character, the front face ofsaid plate being frosted opposite said character.

4, The combination with a closed housing, of a panel closing one sidethereof and comprising a translucent element having an opaque backgroundsurrounding a character opening, means for obstructing and diffusing thepassage of light when entering said element from the front, to suchextent that such light will not be reflected back through said openingto show a legible character when viewed from the exterior of saidhousing, and means arranged within said housing to so illuminate saidpanel that the charaeter will be visible from the exterior of saidhousing when so illuminated, portions of the inner face of saidtranslucent element being formed with a prismatic surface.

5. A sign for the purpose described comprising a closed housing havingone panel thereof provided with a letter 0r character formed oftranslucent material, an opaque background surrounding said letter orcharacter, a frosted surface in front of said letter or character, theback of said letter or character being provided with a prismatic surfaceall in combination With a source of illumination on the interior of saidhousing for lighting and setting off said source of illumination, areflector arranged to effectively focus the light from said source ofillumination upon the back of said letter or character, saidfrostedrface being of such density as .to obstruct. and diffuse lightrays entering said panel from the exterior thereof so as to prevent anyphantom showing of said letter or character.

(i. In a sign, a plate of substantiall y transparent material having araised character on the back thereof and integral therewith, atranslucent screen in front of said character and opposite thereto, andan opaque background having an opening therein through which saidcharacter projects.

T. l, glass panel for an illuminated sign having a frosted front faceand provided on its back with a translucent outlined character, the backof the panel around the character being opaque, and the back of thecharacter having a. 'prismatic surface.

8. A. panel for an illuminated sign comprising an opaque portion and atranslucent portion, means for diffusing light-rays passing through thetranslucent portion comprising prismatic portions on the back of thetranslucent portion, and means for rendering the front of thetranslucent portion non- .distinguishable from the surrounding panelportion when viewed from the front and in the absence of illuminationfrom the rear.

9. A panel for an illuminated sign comprising an opaque portion and atranslucent Jortion said translucent ortion bein rovided at its rearwith prismatic means for diffusing light rays passing therethrough, andmeans for rendering the front of the translucent portionnon-distinguishable from the surrounding panel portion When viewed fromthe front and in the absence of illumination from the rear.

10. A sign panel for an illuminated sign comprising a translucentmember, an opaque member having a character opening therein disposed atthe back of the translucent member, and means including a prismaticsurface for accentuating the character opening when the panel is viewedfrom the front and illuminated from the rear, said translucent memberconcealing the character When viewed from the front and not illuminatedfrom the rear.

11. In an illuminated sign, an opaque panel having a character openingtherein, a

translucent member for said character opening and provided at its rearwith prismatic means for accentuating the character when viewed from thefront and the panel is illuminated from the rear, the character memberand the panel being treated so that the character is not distinguishablefrom the surrounding panel when the sign is viewed from the front andnot illuminated from the rear.

12. A sign panel, for an internally illumi- 'nated sign, having acharacter on the back of the panel, thepanel portions around thecharacter bein opaque, the character and the panel portion alignedtherewith -permitting the passage of ight therethrough, the front of thepanel inL alignment with the character having the propertyof concealinthe character when the panel is illuminate from the front thereof, andthe back of the i0 character having a prismatic face for difpassing'therethrough from the fusing li ht ghe panel.

front of 13. A panel for an illuminated sign'hav ing an opaque portionand a translucent portion the front faces of the opaque and translucentportions being mutually nondistin- ARTHUR B. RAMS'DELL.

